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3DS max UV packing

solidshark91493
polycounter lvl 6
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solidshark91493 polycounter lvl 6
Hi forum. I was advised to post up a thread here about my current WIP. I did some searching but Im still struggling a bit. Working on a game ready tommy gun tutorial from digital tutors. Ive finshed the high poly and low poly versions. Low poly is about 5200 tris. However Im stuck at unwrapping the gun as the tutorial basically gives you a very basic idea of what to do, and thats it.

Ive unwrapped the entire gun (if I can do pieces more efficiently let me know as this is my first uv attempt), But now Im having trouble trying to figure out how to pack all the uv's into the work area. I want to make it efficient, And easy to work with and most of all look good :D

So first, heres a render of the high poly.
Tommygun273.png


Next is a image of the low poly (just a screengrab)
Screenshot_5.png

And heres my unwrap so far, I slowly moved most of it pretty close to the area But it still needs a lot of work.
Screenshot_2.png



So if I can get some assistance and advice that would be amazing! Thanks for checking out my post.

Replies

  • EarthQuake
    When it comes to assets of an sort of complexity, I do all the UV packing manually. Firstly I unwrap each element and move related elements near it into little mini-groups, and then I pack all the groups into the full layout. Auto packing generally sucks, so you gotta do this by hand if you want an efficient layout.

    Also one thing you can do, it looks like you have a lot of cylindrical mapped shapes which result in long rectangles, you can stack all of these up into a nice clean shape. Many of the cylindrical end caps can be capped into odd-shaped holes in the layout for better efficiency as well.

    One thing to keep in mind is you want to make sure your straight edges are straight in the uv layout, so clamp any edges that are slightly skewed, and try not to leave uv islands rotated at random. The reason for this: It takes 1 pixel to represent a straight line but a minimum of two to represent an angled line, so if you line everything up well your texture will appear sharper generally. Your current layout looks to be mostly lined upwell but there are some spots you can tweak.

    Also before you do the final pack, make sure your texal density is even, what this means as that each element in your model has an even resolution. I usually eyeball this by applying a checkered texture and scaling everything until it looks right. After you've done this step you might want to give some areas more or less, for instance iron sights or areas that are real close to the camera should get more resolution, around 125% for items close to the camera and another 125% on top of that for areas you can zoom in on for iron sights view. Areas that won't even be seen, like the back of the buttstock or the front of the barrel can have reduced resolution as well.

    Before you do your final uv packing, you should do a test normal map bake to make sure your lowpoly, smoothing groups and uv layout all work well. I usually make a copy of the uv layout and do a quick auto pack for this purpose. You don't want to find out you need to make a bunch of changes after you've made your final uv layout.
  • solidshark91493
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    solidshark91493 polycounter lvl 6
    Ok so first step is to do a test bake?
    Let it auto pack then do the baking section of the tut?
  • Eric Chadwick
    Nope, read his post again. Auto pack isn't great.
  • EarthQuake
    Actually yes, for a test bake I usually do a quick auto pack, again this is so you can nail down other issues before you finalize the low/uvs. When you get your bake to where you want it without errors, then do the final manual uv packing.
  • solidshark91493
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    solidshark91493 polycounter lvl 6
    Ok, Ill try that today and see what happens. Should I post the test image? I wont know what to look for error wise.
  • EarthQuake
  • solidshark91493
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    solidshark91493 polycounter lvl 6
    Edit* Figured out what I did wrong, didnt have the hipoly selected in the render to texture settings. Per the tutorial I made a light map and a normal map. I think they look awful but Im not too sure yet. So here they are.

    LowpolyLightingMap.png


    LowpolyNormalsMap.png
  • solidshark91493
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    solidshark91493 polycounter lvl 6
    Ok so I adjusted the cage a bit tighter but Im not sure if these are decent or not..

    LowpolyNormalsMap-1.png

    LowpolyLightingMap-1.png

    Hope I can get some advice here.
  • EarthQuake
    Its hard to tell by looking at your maps. Post some images of your normal map applied to the actual mesh.
  • solidshark91493
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    solidshark91493 polycounter lvl 6
    Ok so, First. I got a plugin that packed my maps pretty decently, So heres that and the light map and my super screwed up normal map.

    UV's
    Screenshot_3.png

    Light map
    LowpolyLightingMap-2.png

    Normal map
    LowpolyNormalsMap-2.png

    And here they are applied to the gun. I have the light map in the diffuse slot, And the normal in the bump slot.
    Test.png
  • FelixL
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    FelixL polycounter lvl 4
    Looks like you have a ton of ray misses going on. Look at the meshes in xnormal and activate cage to see where your rays are going.
    Also, as Earthquake said, don't rotate your straight UV shells. A little less texture sharpness is preferable to shells rotated at odd angles and the aliasing/stairstepping artifacts it produces.
  • solidshark91493
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    solidshark91493 polycounter lvl 6
    FelixL wrote: »
    Looks like you have a ton of ray misses going on. Look at the meshes in xnormal and activate cage to see where your rays are going.
    Also, as Earthquake said, don't rotate your straight UV shells. A little less texture sharpness is preferable to shells rotated at odd angles and the aliasing/stairstepping artifacts it produces.

    Well I didnt rotate them I have a plugin that packed them. But I could probly manually move things around. I also dont have xnormal.
  • Mark Dygert
    A few things:

    1) It looks like your low poly is interfering with your light map. Select your low poly, right click and go object properties, then uncheck renderable and bake again. That should take care of the large black patches in the light map.

    2) The normal map appears to be set to world space (lots of yellow, green and red) when most normal maps are tanget (lots of blue). In Render To Texture (press 0) under Projection mapping, click "options..." and set it to Tanget.

    3) Personally I would rather bake a proper ambient occlusion map from VRay or Mental Ray rather than a light map from scanline. The calculation is based on geometry not on the lighting.

    4) Are you rendering your normal maps to png with an alpha channel? because it looks like there isn't a background in your normal map, it would typically be a particular shade of blue. You should probably render to a format that doesn't compress and do weird things with the alpha (like turn it into an opacity map). TGA doesn't compress the image and it leaves the alpha channel as a separate channel. Game engines compress files and it's important that you don't feed it an already compressed image for it to try to compress even more, it comes out looking like garbage.
  • solidshark91493
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    solidshark91493 polycounter lvl 6
    A few things:

    1) It looks like your low poly is interfering with your light map. Select your low poly, right click and go object properties, then uncheck renderable and bake again. That should take care of the large black patches in the light map.

    2) The normal map appears to be set to world space (lots of yellow, green and red) when most normal maps are tanget (lots of blue). In Render To Texture (press 0) under Projection mapping, click "options..." and set it to Tanget.

    3) Personally I would rather bake a proper ambient occlusion map from VRay or Mental Ray rather than a light map from scanline. The calculation is based on geometry not on the lighting.

    4) Are you rendering your normal maps to png with an alpha channel? because it looks like there isn't a background in your normal map, it would typically be a particular shade of blue. You should probably render to a format that doesn't compress and do weird things with the alpha (like turn it into an opacity map). TGA doesn't compress the image and it leaves the alpha channel as a separate channel. Game engines compress files and it's important that you don't feed it an already compressed image for it to try to compress even more, it comes out looking like garbage.



    Ok lot of things im not sure about doing here. xD But I will try some things.

    1. How do I bake without my low poly?

    2.I checked and it is set to tangent.

    3.I do have vray so either would be fine, But I have a hard time figuring out the settings still.

    4.I was currently just so I could see them without opening photoshop, would it really make a huge difference?

    Thanks for the help guys :D
  • EarthQuake
    Honestly I would forget about how the AO map looks right now. Its a huge waste of time to be rendering out AO for test bakes, when you still don't appear to have any idea how your lowpoly looks with the normal map applied (which is the best of a test bake).

    The last normal map you posted was indeed all sorts of messed up, I don't know why. The previous ones you posted looked close to what I would expect, but still appeared to have many errors (probably due to how the smoothing groups were set up).

    Also, even though you found a better way to auto pack your uvs, that is still quite far from a good uv layout, There are many issues with it currently, the biggest being randomly disconnected faces on your uv islands (why does that grip section only have certain quads attached to its uv island?), far too little space between islands (will be a problem when your textures mip down in game) and randomly rotated islands. Not really a problem for a test bake, but I just want to be clear that you still need to put a lot of love into your uvs. You shouldn't look for a quick fix here, but instead should be able to do the job well by hand before relying on plugins.
  • solidshark91493
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    solidshark91493 polycounter lvl 6
    Ok well for now Ill ignore the AO map and remove it from the bake. And I can make any adjustments to the uv's as necessary I dont need to use the plugin. And Im focusing on getting this normal map down first. I dont really know if I unwrapped everything properly and I think the only way Id know is if someone gave my model a once over?
  • solidshark91493
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    solidshark91493 polycounter lvl 6
    While I was waiting, I decided to try xnormal, I put a edit poly modifier on my low poly and put the smoothing groups for everything on one after I cleared them. Then I exported the high and low poly and baked them in xnormal, I got a lot better normal map and heres a render with it applied to the low poly, So this should help now correct?
    Tommygun32.png
  • RyRyB
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    RyRyB polycounter lvl 18
    I would look into a real-time renderer (Toolbag 2 is my choice) for previewing these things. Static renders are nice but seeing the light play across the surface will give you a lot better feedback.
  • EarthQuake
    Yeah its still really hard to see how well the normal map is working here, the material doesn't have any reflectivity and the AO map might be hiding a lot of issues. I would suggest a real time shader, or at least a simple high spec medium gloss material with just the normal map, no ao or anything else.
  • solidshark91493
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    solidshark91493 polycounter lvl 6
    Ok im not sure how to achieve those results, I dont have toolbag 2 and I assume it costs money and for now I cant afford it. Im gonna try to do some new vray renders, See if I can get something thats better for you guys. I also dont have the AO map on it now so should be easier to see any defects, And im considering re doing the UV's manually. Thanks again Im sure its kinda hard dealing with someone that knows as little as I do >.>
  • EarthQuake
    You can get a free 30 day trial of TB2, or use a max shader like 3point lite or Xoliul's shader, but I think current versions of max broke both of these shaders, so it depends on which max you're using.

    There may be some built in shaders these days with max too, not sure, I'm not really a max guy.
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